I've decided to repost this after seeing that quite a few of you folks are still using BizTalk Server 2002 and this question keeps coming up in the newsgroups.

In the BizTalk Server 2002 SDK there is a little utility (written in VB) called the "BizTalk Refresh Messaging Manager Tool" that is used to refresh all document definitions, envelopes, and channels. This is required after you change a document specification or map on your production server. The application lists all the document definitions, envelopes, and channels in separate list boxes. This is helpful because you don't have to start Messaging Manager and manually change each object. To use the tool, simply copy the .EXE file onto your production BizTalk Server and run it. Click the refresh button and watch as it updates document definitions, maps, and envelopes. If it encounters an error while loading an item it will display a message box with the message ERROR LOADING, and will continue. There are three list boxes which display the document definitions, envelopes, and channels.  You can click individual document definitions, envelopes, and channels either with the mouse or by using the space bar to select or deselect the object. The tool's location on your development server is "\SDK\Messaging Samples\Refresh Messaging Manager\BTM_Refresh.exe" under the directory where you installed BizTalk Server 2002.